This invention relates generally to the field of water treatment, and more particularly to a machine and process for treating contaminated water.
In broad terms, the invention provides a waste treatment process wherein contaminated or waste water to be treated is routed directly past at least two electrodes of different polarity and composed of metals which can form multivalent salts and/or noble metals which will not be dissolved. These electrodes are mechanically cleaned on a continuous basis with a device that automatically travels the length and width of the electrodes making contact with the surface of the electrodes to remove any foreign build up on the electrodes.
In a typical electrolytic treatment process, multivalent electrode metal ions are released during electrolysis. The ions cause flocculation of the contaminates in the waste water to be treated. The floc, in turn, absorbs additional components or impurities present in the contaminated stream, thereby serving as a transport medium to remove the organic, inorganic and metal components from the water. The continuous production of ions for flocculation is maintained by the continuous cleaning of the electrodes to eliminate any build up on the electrodes and aids in a uniform electrode consumption.
The electrolytic process has been in existence for many years. In each case, the process equipment has been plagued with a continuous build up of foreign materials on the electrodes causing the electrolysis reaction to diminish or terminate completely and the result is uneven corrosion of the electrodes. Prior patents have attempted to illustrate the use of non-conductive pellets or balls in a fluidized bed to clean the electrodes. Liquid fluid beds with, for example, a 4 ft/sec. Fluidization velocity, are not adequate to remove the deposits from the electrodes. Other patents have indicated reversing the polarity of the electrodes frequently and increasing the velocity of the feed stream contributes to the cleaning of the electrodes. These inventions have met with limited success because this does not remove the non-conducting deposits on reversal of current and high velocity results in non-treatment of the water. After intermediate operating periods (approximately one week), the electrodes inevitably became coated.